Process for preparing alkyl oligoglucosides with a high degree of oligomerization

Abstract

A process for producing alkyl oligoglucosides having a high degree of polymerization involving: (a) providing a fatty alcohol; (b) providing a glucose component; (c) mixing the fatty alcohol and glucose component; (d) acetylizing the reaction mixture by adding an acid catalyst to the mixture; (e) continuously distilling off water from the reaction mixture during acetylization; (f) neutralizing the acid catalyst upon completion of acetylization; (g) removing unreacted fatty alcohol from the reaction mixture; (h) post-polymerizing the reaction mixture to form a final alkyl oligoglucoside product; and (i) neutralizing any remaining acid catalyst and removing any unreacted fatty alcohol from the reaction mixture.

I claim: 
     
       1. A process for producing alkyl oligoglucosides having a high degree of polymerization comprising: (a) providing a fatty alcohol corresponding to formula I:   R.sup.1 OH                                                 (I)        wherein R 1  is an alkyl radical having from 6 to 22 carbon atoms;   (b) providing a glucose component;   (c) mixing the fatty alcohol and glucose component in an initial molar ratio of from 3:1 to 10:1 to form a reaction mixture;   (d) acetylizing the reaction mixture at a temperature of from 90 to 120° C. by adding an acid catalyst to the mixture;   (e) continuously distilling off water from the reaction mixture during acetylization;   (f) neutralizing up to 90 mole-% of the acid catalyst upon completion of acetylization;   (g) removing unreacted fatty alcohol from the reaction mixture until a final molar ratio of fatty alcohol to glucose component of from 1:1 to 3:1 is achieved;   (h) post-polymerizing the reaction mixture at a temperature of from 90 to 120° C. to form a final alkyl oligoglucoside product; and   (i) neutralizing any remaining acid catalyst and removing any unreacted fatty alcohol from the reaction mixture.   
     
     
       2. The process of claim 1 wherein the initial molar ratio of fatty alcohol to glucose component is from 6:1 to 8:1. 
     
     
       3. The process of claim 1 wherein the final molar ratio of fatty alcohol to glucose component is from 1.5:1 to 2.5:1. 
     
     
       4. The process of claim 1 wherein the final alkyl oligoglucoside product has a degree of polymerization of from 1.6 to 2.0. 
     
     
       5. The process of claim 1 wherein the final alkyl oligoglucoside product has a degree of polymerization of from 1.7 to 1.9. 
     
     
       6. The process of claim 1 wherein R 1  contains from 8 to 10 carbon atoms. 
     
     
       7. The process of claim 1 wherein R 1  contains from 12 to 18 carbon atoms. 
     
     
       8. The process of claim 1 wherein the acid catalyst is employed in an amount of from 0.1 to 5% by weight. 
     
     
       9. The process of claim 1 wherein the acid catalyst is employed in an amount of from 0.5 to 2% by weight. 
     
     
       10. The process of claim 1 wherein the acetylization is carried out at a temperature of from 100 to 120° C. and a pressure of from 0.1 to 100 mbar.